Modern telephone systems include many customer features and services that require user/subscriber input to the telephone network subsequent to the initial dial-up performed in the initiation of a call. These features and services may involve interaction with a data base or interaction with a voice mail box for recovery of voice mail messages and/or numerous other operations.
Wireless type portable communication devices typically combine the complete handset and dialing mechanism in a single package. Hence interaction with the telephone network requires one handheld position for receiving audio messages (i.e., tactile ear contact) and a second handheld position (i.e., permitting visual access to the dial mechanism) for operating the dialing mechanism for sending tone and digital messages to the network.
The two modes of operation are incompatible with each other. Either audio contact or visual contact is lost by the user with the handset instrument.